Magnetic separator



1962 c. w. v. DAVIS 3,062,376

MAGNETIC SEPARA'IOR Filed Feb. 26, 1959 I m r l L I/I/IIIIIIII INVENTOR CHARLES W.V. DAVIS a, g E.

AG EN hired States This invention relates to magnetic separators for removing magnetic particles from a fluid in which the particles are entrained and concerns a filter element for such a separator.

A filter element according to the invention comprises a circular framework of substantially non-magnetic material, the said framework including an outer ring defining the periphery of the framework, an inner ring and a plurality of radial members secured to the said rings, together with a plurality of part-annular magnetic members each magnetic member being arranged to fit within the framework in a space bounded by a portion of the inner ring a portion of the outer ring and two of the radial members. Preferably, the framework is provided with a central ring which is positioned concentrically within the inner ring and is secured to the inner ring by further radial members.

A magnetic separator according to the invention comprises a plurality of filter elements as defined above, together with a plurality of steel spacer rings located one between each adjacent pair of elements.

In order that the invention may be readily understood embodiments thereof will now be described by way or" example with reference to the accompanying diagrammatic drawings wherein:

FIGURE 1 shows a plan view of a framework for a filter element,

FIGURE 2 shows a cross-section of two filter elements partly assembled in position,

FIGURE 3 is a view similar to FIGURE 2, showing a second embodiment.

Referring now to FIGURES 1 and 2 a framework 1 for a filter element comprises an outer ring portion 2, inner portion 3 and a central rin portion 4: these ring portions are joined by outer radial members 5 and inner radial members 6 which are secured to the rings. This frame work is of a substantially non-ferrous material and may suitably be formed of brass in which case the rings and radial members may conveniently be secured by soldering. Alternatively, the framework may be of non-magnetic stainless steel in which case it may be found more convenient to weld the rings and radial members to each other. The framework may alternatively be formed of a diecast metal, for instance zinc alloy, or it may be formed of synthetic resin: as however the outer surfaces of the elements are cleaned in use by scraper blades it is preferable to use a metal for the framework as this will be more abrasionresisting than are most synthetic resins.

Within the framework are positioned six part-annular magnet members 8 of which one only is shown in FIG- URES 1 and 2. These members 8 are of a material having a high coercive force and are magnetized in a direction parallel to the axis of the assembly filter, that is to say in a vertical direction as viewed in FIGURE 2. A magnetic material which has been found particularly suitable is that ice known under the registered trade mark Magnadur, this material being a composition consisting substantially of non-cubic crystals principally of a composite oxide of iron and at least one of the metals barium, strontium and lead and, alternatively, of a small amount of calcium as a partial substituent. This material is set forth in US. Patents Nos. 2,762,777 and 2,767,778.

In use a number of filter elements, each with its associated magnetic members 8, are assembled, in the manner illustrated in FIGURE 2, on a central rod or spindle not shown. Between each adjacent pair of elements is provided a steel spacer ring 9, the rings 9 being located in position by lugs 7 secured to the framework 1.

In FIGURE 3 is shown a modified arrangement wherein the lugs 7 shown in FIGURES l and 2 are dispensed with. In this embodiment annular members 10 of non-magnetic material are provided between adjacent filter elements and the steel spacer rings 9 are positioned around the annular members 10. The central ring 4 is in this embodiment of greater axial length than the rings 2 and 3 so that portions 14 of the ring 4 act as locating means for the annular members 10. It is not necessary however for the central ring 4 to be extended in this manner and if preferred the annular members 10 may be dimensioned so that their inner circumference lies flush with the inner circumferences of the rings 4 thus providing within the assembled separator a bore having a flush surface through which the central fixing bolt extends.

It will be observed that the spaces between the inner ring 3 and the central ring 4 in the embodiments shown are left empty so that a certain saving of weight could be achieved by dispensing with the ring 3 and the inner radial members 6. However, this inner ring provides a convenient means for centralizing each element upon a central shaft and so enables the assembly of elements readily to be aligned.

What is claimed is:

1. A filter for a magnetic separator comprising a number of substantially circular frames superposed and spaced from one another, said frames being constituted substantially of non-magnetic material and including an outer ring and an inner ring, a plurality of radial element interconnecting said outer and inner rings at spaced intervals to form a multiplicity of enclosures which together constitute a ring-shaped structure, a plurality of magnetic members each corresponding to the shape of a corresponding enclosure and inserted therein, each magnetic member having curved surfaces co-extensive with and adjacent to both said inner and outer rings, a plurality of spacer rings located between superposed frames, a plurality of lugs secured to said frames for locating said spacer rings, said lugs being disposed on each of said frames in a circle concentric with and disposed radially inward from said outer ring.

2. A filter for a magnetic separator comprising a number of substantially circular frames superposed in spaced relationship and each being constituted substantially of non-magnetic material, each of said frames including an outer ring, an inner ring and a central ring, said central ring having portions thereon forming locating means, a plurality of radial elements interconnecting said outer and inner rings at spaced intervals to form a multiplicity of enclosures which together constitute a ring-shaped structure, a plurality of magnetic members each corresponding to the shape of a corresponding enclosure and inserted therein, each magnetic member having curved surfaces coextensive with and adjacent to both said inner and outer rings, a plurality of non-magnetic annular members posi- 5 tioned between said superposed frames and having their inner surfaces abutting against said locating means, a plurality of steel spacer rings positioned between superposed frames and located on the outside of said annular members and having the inner surfaces thereof abutting the outer 10 surfaces of said annular members.

References Cited in the file of this patent UNITED STATES PATENTS Frantz May 23,

Anderson Sept. 7,

FOREIGN PATENTS Germany Oct. 20,

Great Britain Jan. 9,

Great Britain Sept. 3,

France Mar. 29, 

